First portion of data structure to start from

[Anatoly Volynets <av@total-knowledge.com>]

Now, I want some clarifications:

Person to Course relation:
 Type: many to many ------ means many people can relate to the same 
course, while a person can relate to many courses
 Fields:
   type (student/apprentice/author) ----- so these are fields of the 
intermediate table?

BTW, I am not sure, I remember what exactly an apprentice is here? A 
co-author or teacher with some limited rights or a student with some 
expanded duties (makes sense if we talk about a group of students)? Any 
suggestions?

Topic to Required Topics relation:
 Type: one to many ----------- means a topic can be optional or 
mandatory? We have related issue in specs: prerequisites for a topic, 
but it seems to be much complicated. There can be many 
topics/courses/texts/problems/tests/games/other objects pre-required for 
the given topic, or course,  or  problem, or  game, or....  Thus we 
need  to  provide  one-to-many prerequisite-relation for an object in a 
course to objects from Repository (I start to think)?

 Fields:
   type (optional/mandatory)

Person to Topic relation
 Type: many to many
 Fields:
   type (assigned,study,competed,apprentice,teacher)

Keyword to Topic relation
 Type: one to many
 Fields:
   keyword

One keyword an be used in many topics, courses and so forth, while many 
keywords can be used in a course, topic, explanation, etc. So it is 
many-to-many and involves many objects, not only topics.

Explanation to Topic relation
 Type: one to many ---- if one-to-many, then Topic to Explanation: 
there supposed to be many explanations for a topic

Explanation to Person relation - I'm not sure we need this at all
 Type: one to many

Explanation
 Fields:
   name,
   reference to source, ---- Why we need this? If an author refers 
students to a text from Repository instead of writing his own text (next 
field)? I think this situation does not differ from usage of other objects.
   text

Person
 Fields:
   first name,
   last name,
   address,
   email

Topic
 Property of: course
 Fields:
   title,
   summary,
   problem ------- there can be a lot of problems within a topic



Course
 Property of: author(s)
 Fields:
   name,
   description


--
Alexey Parshin,
http://www.sptk.net